I have many conversations about diet and exercise here at the office, often after the person to whom I’m talking has been told they have “insulin resistance” and should start some new medication.
But when I ask if anyone explained what insulin resistance is, the answer is almost always no. And knowing, as they say, is half the battle. So, allow me to explain.
Insulin is a storage hormone. It’s made in the pancreas, the organ that senses increases in blood sugar, which triggers insulin to be released to tell that blood sugar (glucose) to be stored (the storage form of glucose is called glycogen).
There are two places where glucose is stored: the liver and your muscles.
To explain insulin resistance, I compare those two storage areas to hotel parking lots. Cars enter the freeway (glucose enters the bloodstream), and the traffic cop (the pancreas) wants them off the street and parked.
But you’ll run out of parking space if there are too many cars. The traffic cops still won’t like all the traffic, so they’ll keep directing cars into the lot. The hotels won’t like all the extra traffic, so at first, they’ll turn on the “no vacancy” sign. On a cellular level, the “no vacancy” sign is the first bump in insulin resistance, and that bump will cause an increase in fat storage and a bump upward in cholesterol.
Keep adding traffic, though, and the hotel manager gets more irritated. He is so annoyed that he builds a gate that goes down in front of the entrance to keep cars from entering at all. On the cellular level, this is called the “downregulation of insulin receptors.” In other words, muscle cells reduce the number of insulin receptors available since the cells are full of glycogen, and there’s nowhere to put more.
Once the arms go down—the downregulation of insulin receptors—you’ve reached full-on insulin resistance. This eventually wears out the beta cells in the pancreas, leading to diabetes.
So–Insulin resistance. Not good. But what do you do about it?
I’m glad you asked.
There are a few strategies to regain your sensitivity. To return to the parking lot analogy, you can add more parking spaces and/or (preferably both) decrease the traffic trying to park.
If you decrease calories, you decrease traffic to the hotel parking lot. The calories that make the most sense to decrease are processed carbohydrates–things high in calories but low in nutritional value. I make the case in my books that someone with a lot of fat to lose can cut carbs quite a bit.
In my recent article about zone two training, I mentioned that those with the most mitochondrial dysfunction will have the most difficulty accessing their fat stores for fuel. I had a patient just yesterday who I hadn’t seen in a while and had lost around 50 lbs since I’d last seen him. When I asked him about his strategy for losing weight, he replied, “Walking.”
Walking, especially for someone who hasn’t been exercising, is enough to nudge the body into a much more positive metabolic state. The patient in question told me he gets up early, walks for a while, and then does more at work and lunch, about eight miles a day.
And walking eight miles a day burns about as many calories as running the same distance–it just takes longer.
So, to clear the parking lot, eat less cars, and walk some of them off. Those are the “decrease the traffic” strategies.
My next strategy is to add parking spaces. You can’t add more liver, but you can add more muscle. The best way to add muscle is to lift weights and get stronger. You don’t have to spend hours in the gym to do that. I only lift three days a week, and each session lasts about 30 minutes.
I admit that I push myself hard for those 30-minute sessions, but nothing worth having comes easily, and keeping my strength and resilience as I age is worth an hour and a half a week under a barbell.
The final piece of good news on this subject is that as you empty those parking spots while simultaneously building more, your insulin sensitivity will improve, which means you can eat more carbs to fuel your workouts. I love carbs, so I keep the workouts going.